Bovine circumvallate papilla is employed as our study system. Papillae on the mounted area of the bovine tongue contain no taste buds, and are therefore used for control studies. Plasma membranes of the circumvallate papillae have been isolated in pure forms as indicated by marker enzyme studies and by electron microscopy. Other subcellular membranes were also isolated for comparative studies. The circumvallate plasma membranes solubilized in sodium dodecyl sulfate showed a total of 21 electrophoretic peaks on polyacrylamide gel. Most of them are PAS-positive. At least two of the glycoprotein bands are present only in the circumvallate. The major neutral lipids found in the membranes are cholesterol and triglycerides. The major polar lipids are sphingomyelin, phosphotidyl cholin, and phosphotidyl ethanolamine. These are also the major lipid classes found in the whole papillar tissue. They represent 80% of the total lipid in each category. Most of the lipid classes are present in the gustatory tissues, except that phosphotidyl inositol is found only in trace amount. We studied the metabolic activity of the circumvallate papillae, and found high specific activity for pyruvate kinase and lactic dehydrogenase, indicating the cells of bovine gustatory tissue have active glycolytic process. Further studies are currently under way.